Follicle stimulating hormone and fibroblast growth factor-2 interact and promote goat primordial follicle development in vitro

The aims of the present study were to investigate the effects of the interaction between follicle stimulating hormone (FSH) and fibroblast growth factor- 2 (FGF-2) on survival, follicular growth initiation and further growth of caprine preantral follicles. Pieces of caprine ovarian cortex were cultured for 1 or 7 days in minimum essential medium (MEM) supplemented with FSH, FGF-2 or FSH+ FGF-2. Small fragments from non-cultured ovarian tissue and from those cultured for 1 or 7 days were processed for classical histology and transmission electron microscopy (TEM) to verify follicular morphology and growth. The results showed that, after 7 days culture, the highest percentages of normal follicles were observed in medium supplemented with FSH. After 7 days culture, the interaction between FSH and FGF-2 was most effective to promote the initiation of primordial follicles growth and oocyte growth. TEM showed ultrastructural integrity of follicles after 1 day of culture in MEM and after 7 days in all treatments, except in those follicles cultured for 7 days in MEM. In conclusion, this study demonstrated that the interaction between FSH and FGF-2 stimulates the initiation of primordial follicles growth and the subsequent growth of developing follicles. Furthermore, these data showed that FSH is important to maintain follicular integrity after 7 days culture.